I have nothing against dancing for victorys but its poor sportsmanship if you do so on a corpse.
And it doesnt matter if you "Kill" them or "KOed" them, its still a Game like Sports are Games, people know the term E-Sports?
While its nothing compared to the Tournament and League stuff its similar just on a casual base.

I dont really give a damn if someone does it nor does it affect me in anyway, i just think its pathetic and it does reflect the image of the average player being immature. (doesnt matter which Game)